铁道建筑

建立合理的铁路石拱桥有限元模型是分析其结构静动力学性能的基础，常用的实体单元模型虽然计算精度较高但是计算工作量较大，因此提出一种基于三维空间梁单元的计算模型十分必要。首先，建立石拱桥的实体单元模型，分析静力荷载的传递机制。然后，根据力传递机制分析结果，建立石拱桥的三维空间梁单元简化计算模型。最后，对比两种计算模型的静动力计算结果，验证三维空间梁单元计算模型的准确性。结果表明：本文提出的三维空间梁单元简化计算模型可以用铁路石拱桥的静动力学分析，为铁路石拱桥的合理化建模提供了参考。

Establishing a reasonable finite element model for railway stone arch bridges is the basis for analyzing their static and dynamic structural performance. Although the commonly used solid element model has high calculation accuracy， it involves a large amount of computational work. Therefore， it is necessary to propose a calculation model based on three-dimensional spatial beam elements. Firstly， a solid element model of the stone arch bridge is established to analyze the transmission mechanism of static loads. Then， based on the analysis results of the force transmission mechanism， a simplified calculation model of the stone arch bridge using three-dimensional spatial beam elements is established. Finally， the static and dynamic calculation results of the two calculation models are compared to verify the accuracy of the three-dimensional spatial beam element calculation model. The results show that the simplified calculation model based on three-dimensional spatial beam elements proposed in this paper can be used for the static and dynamic analysis of railway stone arch bridges， providing a reference for the rational modeling of railway stone arch bridges.